1. Field of the Invention
The present invention relates to a sheet processing apparatus that performs binding processing on sheets and an image forming system with the sheet processing apparatus.
2. Description of the Related Art
Conventionally, a sheet processing apparatus with a binding unit that performs binding processing on a sheet bundle including a plurality of sheets has been known, and an image forming system with the sheet processing apparatus has also been known.
For example, in a sheet processing apparatus only with a binding unit that binds a sheet bundle using a metal needle being a binding member, a binding failure may occur because a needle is too long when a sheet bundle including a small number of sheets is bound.
Moreover, in a sheet processing apparatus only with a binding unit such as crimp binding and half-extraction binding that binds a sheet bundle without using a metal needle, a binding failure may occur because a thick sheet bundle cannot be bound.
Japanese Laid-open Patent Publication No. 2011-207560 describes a sheet processing apparatus that includes a first binding unit that binds a sheet bundle using a metal needle and a second binding unit that is disposed in a position opposite to the first binding unit and binds a sheet bundle without using a metal needle.
As is the sheet processing apparatus described in Japanese Laid-open Patent Publication No. 2011-207560, a sheet processing apparatus that includes a plurality of binding units having different binding processing makes it possible to perform binding processing by using an optimal binding unit, thus preventing a binding failure.
However, in the sheet processing apparatus described in Japanese Laid-open Patent Publication No. 2011-207560, the first binding unit and the second binding unit are arranged at opposite positions, and this leads to a problem that the apparatus is upsized.
In view of the above, there is a need to provide a sheet processing apparatus capable of preventing a binding failure while suppressing upsizing of the apparatus and an image forming system with the sheet processing apparatus.